The present invention relates to oil and grease seals and more particularly, to a reusable gasket assembly or composite seal for drive axles.
It is customary today to have a number of trucks or tractors delivered as a unit. In order to save transportation costs, it is customary for one tractor to drive to its destination with several other tractors attached to the same in a "piggy-back" formation. In this way, it is not necessary for the tractor to be driven several hundred miles or more when it has no useful load on it.
When operating a "piggy-back" arrangement, it is customary for the axles to be pulled from their housing and placed inside the cab or other suitable location. In order to do this, the bolts holding the axle are pulled and the axles are simply removed for transit. Thereupon, an expedient is relied upon, such as placing some rags or other articles at the ends of the axle housing.
In this way, the differential gears are not required to operate and the wheels may turn without turning the differential gears inside the housing. When one arrives at the destination, the axles are removed from their place of storage and are replaced in the axle housing. Thereupon, the former material situated between the axle and the housing is reused or discarded.
The customary practice in this area has been to use a paper gasket glued to the wheel hub. With the paper gasket, when the axle is removed from the wheel hub, there is the problem of replacing it without leakage, inasmuch as an adhesively affixed gasket invariably causes some of the gasket to be removed with the axle and some to remain on the hub. Therefore, installing a new paper or new gasket material involves scraping and cleaning both of these parts, inserting a new gasket and affixing the axle to the hub. Rushing this task leads to imperfect seals and leakage from the hub.
In another case, the hub may be designed for use with an O-ring, in which case the O-ring is removed, the vehicle is driven, and then the O-ring is replaced. This plan, which is theoretically acceptable, has several practical drawbacks. First, the O-ring is susceptible of stretching and/or losing its installed dimension, especially when placed in storage for a day, a week, or other suitable interval. The second is that, when returning the O-ring to its groove, the ring may not fit exactly into the groove and may thereupon produce a leaking seal between the hub and the axle. This difficulty is exacerbated by the inaccessibility of the O-ring groove once the cap has been placed thereover. Misalignment, and consequent leakage, occurs quite readily with O-ring type seals.
Accordingly, there has been a need for a simple, inexpensive seal or gasket for the axle which would enable the axle to be removed one or more times and replaced without damage thereto or without loss of lubricant. Ideally, such a seal should be relatively inexpensive. Another advantage would be to provide a seal for axle hubs which would be readily removable but completely resealable one or more times.
An ideal seal would be one which fits into a clearly defined space in the hub, and which is removable and reusable without difficulty.
Another advantage of a proper seal would be one wherein the seal would bend or "oil can" outwardly when subjected to an axial force, but which would be freely removable when allowed to spring back by its own innate resiliency to a very slightly smaller dimension so as to be readily removable by hand.
Accordingly, it is an object of the invention to provide an oil seal of improved convenience and reliability for drive axles.
Another object of the invention is to provide a removable oil seal which would fit into a designated counterbore, but which would be readily removable therefrom.
Yet another object of the invention would be to provide a seal with a rubber component and a metal component, which could be forced into an oil-tight sealing position when the axle is snugly installed in the hub.
Still another object of the invention would be to provide a stiffener having a base portion, a slightly angled wall, and a radial flange directed inwardly, and having the o.d. of the seal covered by a bonded rubber component which extends axially beyond the extent of the stiffener or casing, at least in one direction.
A further object of the invention would be to provide a rubber o.d. seal having a pair of sealing beads on its end face, and having a metal stamping or casing including an axial or nearly axial portion, a slightly inclined portion and a third component of the metal which extends radially inwardly and which is partly covered by the rubber forming the seal.
A still further object of the invention is to provide a seal wherein the stamping or casing is made from metal, and wherein the rubber makes contact with the housing and with the axle flange along different, perpendicular surfaces.
The invention achieves its objects by providing a method of sealing an axle flange to a hub which includes forming a counterbore in the hub, placing therein a rubber o.d. seal having an axial portion for engaging the axle end, and wherein this portion is supported by a casing having both an axial and radial component. The invention also achieves its objects by providing a seal with a contoured end face, a sidewall, and a stamping or casing of generally L-shaped configuration, arranged to fit in a counterbore wherein axial deflection will cause limited radial bulging and consequently, a tight fit to the seal.
The manner in which the foregoing and other objects and advantages are achieved in practice will become more clearly apparent when reference is made to the following detailed description of the invention wherein a preferred embodiment of the seal of the invention is set forth by way of example, and wherein such seal is shown in the accompanying drawings, in which like numbers indicate corresponding parts throughout.